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Information Security.
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| // coded by Anuj Jha | |
| // Caesar Cipher encryption-decryption | |
| //caution : avoid special character. | |
| import java.util.Scanner; | |
| public class CaesarCipher { | |
| static int[] encryption(int[] charArray, int key){ | |
| for(int i = 0; i < charArray.length;i++){ | |
| if(charArray[i] <=90) //for UPPERCASE | |
| charArray[i] = ((charArray[i] + key -65) % 26) + 65; | |
| else //for lowercase | |
| charArray[i] = ((charArray[i] + key -97) % 26) + 97; | |
| } | |
| return charArray; | |
| } | |
| static int[] decryption(int[] charArray, int key){ | |
| for(int i = 0; i < charArray.length;i++){ | |
| if(charArray[i] <=90) | |
| charArray[i] = ((charArray[i] - key -65 + 26) % 26) + 65; | |
| else | |
| charArray[i] = ((charArray[i] - key -97 + 26) % 26) + 97; | |
| } | |
| return charArray; | |
| } | |
| /** | |
| * Function that generates array of integer type for each char with their equivalent ASCII value. | |
| *to generates array of char type use the syntax below:- | |
| * char[] charArray = new char[val.length()]; | |
| **/ | |
| static int[] charArrayGenerator(String val){ | |
| int[] charArray = new int[val.length()]; | |
| for(int i = 0; i < val.length(); i++) | |
| charArray[i] = val.charAt(i); | |
| return charArray; | |
| } | |
| //print Array by converting ASCII to respective character value. | |
| static void printArray(int[] temp){ | |
| for (int value : temp) System.out.print((char)value +" "); | |
| } | |
| public static void main(String[] args){ | |
| Scanner input = new Scanner(System.in); | |
| while(true){ | |
| System.out.print("\nENTER YOUR TEXT : "); | |
| String val = input.next(); | |
| System.out.print("ENTER YOUR KEY : "); | |
| int key = input.nextInt(); | |
| int[] charArray = charArrayGenerator(val); | |
| System.out.print("\n 1. PLAIN TEXT --> CIPHERED TEXT" + | |
| "\n 2. CIPHERED TEXT --> ORIGINAL TEXT \n Other to EXIT\n"); | |
| System.out.print("\n Enter choice : "); | |
| int choice = input.nextInt(); | |
| switch (choice){ | |
| case 1: | |
| System.out.print("\nPLAIN TEXT : "); | |
| printArray(charArray); | |
| int[] cipheredTextArray = encryption(charArray,key); | |
| System.out.print("\nCIPHERED TEXT : "); | |
| printArray(cipheredTextArray); | |
| break; | |
| case 2: | |
| System.out.print("\nCIPHERED TEXT : "); | |
| printArray(charArray); | |
| int[] plainTextArray = decryption(charArray,key); | |
| System.out.print("\nPLAIN TEXT : "); | |
| printArray(plainTextArray); | |
| break; | |
| default: | |
| break; | |
| } | |
| } | |
| } | |
| } |
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| import java.util.Scanner; | |
| public class monoalphabetics { | |
| private static void printArray(char[] arr){ | |
| for(int i = 0; i < arr.length; i++){ | |
| System.out.print(""+arr[i]); | |
| } | |
| } | |
| public static void main(String[] args){ | |
| Scanner input = new Scanner(System.in); | |
| char[] PlAr = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',' '}; | |
| char[] ChAr = {'b','d','f','h','j','l','n','p','r','t','v','x','z','a','c','e','g','i','k','m','o','q','s','u','w','y',' '}; | |
| System.out.print("Enter Plain Text: "); | |
| String PT = input.nextLine(); | |
| char[] CT1 = new char[PT.length()]; | |
| for(int i = 0; i < PT.length(); i++){ | |
| for(int j = 0; j < ChAr.length; j++){ | |
| if (PT.charAt(i) == PlAr[j]) { | |
| CT1[i] = ChAr[j]; | |
| } | |
| } | |
| } | |
| System.out.print("\nCipher Text : "); | |
| printArray(CT1); | |
| System.out.print("\nEnter Cipher text :"); | |
| String s1 = input.nextLine(); | |
| char[] res = new char[s1.length()]; | |
| for(int i = 0; i < s1.length(); i++){ | |
| for(int j = 0; j < ChAr.length; j++){ | |
| if (s1.charAt(i) == ChAr[j]) { | |
| res[i] = PlAr[j]; | |
| } | |
| } | |
| } | |
| System.out.print("\nOriginol Text : "); | |
| printArray(res); | |
| } | |
| } |
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| import java.util.Scanner; | |
| public class monoalphabeticsAttack { | |
| private static void printArray(char[] arr){ | |
| for(int i = 0; i < arr.length; i++){ | |
| System.out.print(""+arr[i]); | |
| } | |
| } | |
| private static int charCount(char[] arr, char ch){ | |
| int count = 0; | |
| for(int i = 0; i < arr.length; i++){ | |
| if(ch == arr[i]){ | |
| count = count + 1; | |
| } | |
| } | |
| return count; | |
| } | |
| public static void main(String[] args){ | |
| Scanner input = new Scanner(System.in); | |
| char[] plainTextArr = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',' ',',','.','-'}; | |
| char[] cipherTextArr = {'b','d','f','h','j','l','n','p','r','t','v','x','z','a','c','e','g','i','k','m','o','q','s','u','w','y',' ',',','.','-'}; | |
| System.out.print("Enter Plain Text: "); | |
| String PT = input.nextLine(); | |
| char[] CT = new char[PT.length()]; | |
| for(int i = 0; i < PT.length(); i++){ | |
| for(int j = 0; j < cipherTextArr.length; j++){ | |
| if (PT.charAt(i) == plainTextArr[j]) { | |
| CT[i] = cipherTextArr[j]; | |
| } | |
| } | |
| } | |
| System.out.print("\nCipher Text : "); | |
| printArray(CT); | |
| System.out.print("\n"); | |
| //Counter | |
| for(int i = 0; i < CT.length; i++){ | |
| System.out.print("\n"+CT[i]+": "+charCount(CT,CT[i])); | |
| } | |
| } | |
| } |
Author
AnujJha-stack
commented
Dec 18, 2019
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